Circuit interrupting and isolating switch



Oct. 22, 1957 A. c. SCHWAGER 2,810,805

CIRCUIT INTERRUPTING AND ISOLA'IING SWITCH Fil ed Oct. 3, 1955 2Sheets-Sheet 1 IN V EN TOR.

AUGUST 0.5GHWAGER.

W W h 4rrnrmr/ Oct. 22, 1957 A. c. SCHWAGER CIRCUIT INTERRUPTING ANDISOLATING swncu Filed Oct. 3, 1955 2 Sheets-Sheet 2 INVENTOR.

AUGUST 6. SGHWAGER.

1 Av! m/ United States Patent CIRCUIT INTERRUPTING AND ISOLATING SWITCHAugust C. Schwager, Portland, Oreg., assignor to Schwager-WoodCorporation, Portland,- Oreg., a corporation of Oregon ApplicationOctober 3, 1955, Serial No. 538,145

Claims. (Cl. 200-145) This invention relates generally to air-breakswitches, and more particularly to a power line circuit isolating switchassembly of the type employing an air-break switch and an arcsuppressing circuit interrupter which will open a power line circuitirrespective of fault currents, load currents, capacitor and linecharging currents, magnetizing currents, etc., without an externaldisplay of an are or flame.

The main object of my invention is to provide a disconnecting switchcapable of interrupting load or charging currents and fault currents ofa transmission line without the external display of an are or flame.

Another object of my invention is to provide a circuit interruptingdevice capable of interrupting load currents and having a form suitablefor movement as a wholeinto and out of engagement with at least one lineterminal so as to insert an appropriate isolating air-gap in the circuitfollowing circuit interruption.

A further object of the invention is to provide a circuit protectivedevice embodying two serially related circuit interrupting units capableof interrupting load and over load currents, and at least one of whichis movable out of the circuit for inserting a circuit isolating air-gaptherein.

A further object of the invention is to providea load breakdisconnecting switch wherein a movable switch blade operates toestablish an air-break in the circuit and a circuit breaker withcompletely enclosed separable contacts operates to interrupt currentflow and open the circuit in response to the initial movement of theswitch blade to its circuit isolating position.

A further and more specific object of the invention is to provide a loadbreak disconnecting switch in which the switch blade is connected atleast during its opening movement with an arc extinguishing circuitbreaker for causing current normally flowing through the switch to betransferred to the are extinguishing circuit and in which the arcextinguishing contacts are actuated to an open circuit position upon aninitial opening movement of the switch blade.

Finally and more specifically another object of my invention is toprovide a novel circuit isolating switch means embodying an arcsuppressing circuit breaker of moderate current carrying capacity and anair-break disconnecting switch having a blade of the so-calledbeavertail type, in which a shunt circuit forming means operable upon afinal twisting of said switch blade into its circuit closed positionestablishes a current carrying shunt 4 circuit in parallel with saidcircuit breaker and upon an initial twisting of said switch bladepreparatory to a pivotal circuit disconnecting operation said shuntcircuit is opened.

Another object of my invention is to provide a disconnecting switchembodying trip-free circuit breaker in series circuit with adisconnecting switch blade of the type having both a pivotal and atwisting motion preceding and following respectively a circuit openingand a ice circuit closing pivotal movement of said switch blade, inwhich means timed with the twisting motion of said switch blade operatesto respectively open and close the circuit through said circuit breakeras said switch blade is twisted out of and into its circuit closedposition with respect to its terminal contact.

Other objects and advantages of the invention will be in part evident tothose skilled in the art and in part pointed out hereinafter inconnection with the accompanying drawings wherein there is shown by wayof illustration and not of limitation a preferred embodiment thereof.

In the drawing:

Figure 1, is a side elevation of a switch embodying the invention,

Figure 2, is a plan view of the switch, as shown in Figure 1 of thedrawings,

Figure 3, is an enlarged plan view corresponding to that portion asshown in Figure 2 of the drawings,

Figures 4 and 5 are fragmentary views similar to Figure 3 showing theswitch blade operating mechanism in different operating positions, and

Figure 6, is a fragmentary view showing a modified embodiment of theinvention.

In the past, numerous air-break switches have been designed to operatein conjunction with an arc rupturing circuit breaker either installedand associated therewith or incorporated in the structure of theair-break switch blade. Such are interrupting devices are at the presenttime in the form of circuit breakers having contacts that are immersedin oil, or subjected to an oil blast, a gas blast, or are of theexplosion type. Devices of this character require the introduction of alarge break or contact separation, which may vary from several inches toseveral feet, and consequently they also require a complicated andmassive operating mechanism and usually operate with considerableexternal flame with its associated hazards. In addition to this the lifeof such circuit interrupting devices is limited, either due tocarbonization of the oil or wear of their component parts, andconsequently they require frequent inspection for maintenance and evenreplacement of parts.

In the transmission of electrical power, the disconnecting switchheretofore has been used mainly to isolate sections of a powertransmission system from each other or for isolating a load circuit froman associated network.

This switching operation in most instances necessarily had to be carriedout under conditions of no-load on the circuit and even under no-loadconditions, the high voltages now employed in power transmission systemspro duce charging currents of appreciable magnitude. In the past,attempts have been made to interrupt line charging currents and lightload currents with disconnecting switches equipped with arcing horns andwhile certain of these disconnecting switches, particularly those of thelow-voltage type, have successfully interrupted charging and small loadcurrents, their use for this purpose is unsatisfactory as the exposedair-break arc drawn during the circuit opening operation may be blownacross the line or to grounded parts thus causing a flow of 1 faultcurrents.

Briefly, and. for the purpose of this disclosure. itmay be stated thatthe vacuum circuit breaker employed by me has separable contacts thatare enclosed within a hermetically sealed tubewhich is evacuated. tothe:highestv possible vacuum, forv example,.10?mm. Hg:or;mor.e=. The arequenching and insulating quality of the contact; gap. in a vacuum isextremely high and'is inithe. order: of one million volts per 0.1 inchofcontactzseparation. Imother:

words, when the contacts carryingan.alternatingacurrent separate, a.contact separation: of; about. one-tenth of an inch will be. sufiicientto openthe: circuit under. all con, ditions. of. operation. When.employedlin. the: manner herei contemplated; the vacuum switch-hasbeen'iound tov produce .an; extremely. 'eflicients interruption of; aahighlvolttage circuit under both load and fault conditions.

With such a circuit breaker, interruptiornofthe:circuit always; occurs;at; the first current lzero. following the; separations of contacts anddue to the high insulating value. offthevacuuminthe gap,.re-strikes.donot; occurteven under the most severe switching operations; such as'are'met within switching capacitor. banks; orrinthe opening of long linepower transmission systems. Due to. the complete absence of gasmoleculesaround the contacts of such ,a. circuit breaker, the. are.formed is extremely small as compared with the; arcproduced inother.types of circuit interrupting devices suchqasihave beenzreferred toherein-above. little deterioration of the contactsand consequently largecapacitor. banks.- can; be switched several thousand and possiblyseveraliten, thousands oftimes. Such a, vacuum switch can therefore: beleft in service for the lifetime of.

the. associated equipment without requiring maintenance,

replacement 1 or. repair. I

Air-break'switches of the typecontemplated by this invention are usuallybuilt. with'continuouscurrent rat ings-of. from.- 600 to 12.00 amperesand while vacuum switchesucanrinterrupt such currents and even highervaluesthey become uneconomical. if designed for such a:continuouscurrent .carryingrating. The acceptable continu-- ous currentrating forrvacuum switchesisin the-neighborhoodof 100. toZOO amperes.Therefore in order toemploy such acircuitbreaker it.is.advisableto-place the vacuum switch in shunt. circuit with an associated currentcarrying conductor or auxiliary shunt formingswitch blade, which willoperate to. carry the. line current during normal closed circuitoperation of the disconnecting switch. In this-arrangement the auxiliaryor shunt circuit forming blade is opened prior toa circuit interruptingoperation of. thetvacuum switch and-the vacuumswitch.

isoperated. to .interrupt the flow of. current during the initial.circuitopeningoperation of the mainair-break.

Switch? As. shown the.vacuum insulated. circuit. breaker; 11 has axiallyaligned and cooperating contacts 7.. and*8 -65 upper contact 7 in thisinstanceis. stationary and the. lower. contact 8. ismovable between.itscooperating limits; asthe circuit therethrough is.- opened and.closed in the/ which are mountedwithin an evacuated envelope 9. The

manner to appear. hereinafter. The switchbladelO engagesa stationaryswitch:blade contactterminallz. and. the circuit breakerllhas aline.terminal-13. Extending upwardly from theswitch. blade .10thereis-an auxiliary. shunt circuit forming blade14 whichengagesaterminal. contact clip carriedby. the circuit breaker terminal13:

In this instance the circuit breaker ll is mountedaupon As a resultthereisvaccordingly very a. bracket. 16 carried. by an insulating stack17 and the switch blade 10 is shown as pivotally mounted upon a bridgingmember 18 that extends from the top of the insulator stack 17 to asecond insulator stack 19. This insulator stack 19 is rotatable in theconventional manner as a means for operating the switch blade 10 intoits openand closedcircuit positions. A third insulator stack 20 carriesa line terminal 21 and also the switch blade terminal contact 12 withwhich the switch blade 10 cooperates;

A feature of. the invention resides in the utilization of a novelfeature of the so-called beaver-tail twisting mechanism by which theswitchv blade 10 is. rotated or twisted about its axis as it moves intoand out of circuit forming engagement'with its-stationary contactterminal 12. In this particular arrangement the switch blade ll) iscarried by a supporting member 22 that is pivotally mounted'upomthe;bridgingmernber 18. anditheupper end bridging.member; 18; so that it;may be rotated. At. its

lower end theinsulator. stack. 19 has a double. ended diametricallyextending-levextarm'23 by which this stack. either alone. orn'together.withsa corresponding stack. of a similar switch. or switches may besimultaneously operated. At its upper end the insulator stack 19 is alsoshown: as havinga radially extending arm. 24 tothe outer endof whichthere: is. connected a forked link 25. This forked link. isshownasspanningtheswitch blade 10 and as connected to trunnions 26carried by a rotatable hearing 2.7- to whichthe. switch blade. 101's.attached. As will hereinafter appear, the auxiliary shunt circuitforming blade 14isrnounted directly upon one side of the forkedIink'ZSand asthis forked link25 operates to impart a twisting motion totheswitch blade 10 the auxiliary shunt forming blade 14 willbe-caused toswing laterally in a planersubstantially at a-rig-ht-angleto the. planein which the switch blade. 101pivots and: out of contact with the switchclip 15.. To compensatefonweight and to provide for balanceand easeofoperationthe bridging member 1.8. is shown asencompassing acounter-balancing spring means 28;

In order: to justify the. employment. ofan air-break disconnecting.switch blade in combination with an inexpensive. arc extinguishing.circuit breaker, inthe manner. heredescribed, instead of. a conventionalhigh-voltage circuitbreaker with full load current. capacity as in thepast, it. isessential that the circuit. breaker. ofthe cornbination belight in construction; and operable. with a simple: and. inexpensive.-operating mechanism. In. the

constructionofa circuitbreaken-of. the. latter type the.

current carrying. contacts. willnecessarily beof low current:carryingcapacity and :consequently itis. the. practice to-providev a.circuit breaker short-circniting shunt that will cooperate with; the;circuit breaker as a current carrying; conductor. when the disconnectingswitch blade. 10 is...i'n.its. circuit. closedv position. To provide theabove features I prefer to use a circuit controlling switch of thesealedvacuum. insulated type,.as. such. a. switch has been found: tohave the capacity. to carry the full line The; above: arrangements;except for: the addition of. the arc. extinguishingcircuit' breaker; 11and. its: auxiliary To accomplish this, however, it is necesshuntcircuit forming blade 14 may be considered to represent construction ofpractically any of the so-called beaver-tail types of air-breakdisconnecting switches in which the circuit isolating blade 10 isrotated or twisted into and out of engagement with its co-operatingterminal contact, here designated by the numeral 12. While I have shownonly one such disconnecting switch with an associated circuit breaker itwill be understood that two or more of these switches may be used inparallel on a power line and operated simultaneously by connecting linksextending between the ends of the doubleended diametrically extendinglever arm 23 carried by the rotatable insulator stack 19. At the upperend of the insulator stack 19 and in addition to the radial arm 24 thereis a shorter lever arm 29 to which there is universally connected acircuit breaker control rod 30 that operates with a reciprocatingmovement as the switch blade 10 is twisted and pivoted upon its support22. This operating rod 30 is shown as connected with a crank arm 31 thatextends from and controls a circuit breaker contact operating mechanism32 which may be of any conventional form. As will be pointed out in moredetail in my co-pending application for patent the position andoperating range of the lever arm 31 of the operating mechanism 32 is sorelated to the operations of the switch blade 10 that the circuitopening and circuit closing movements of the circuit breaker contactswill respectively occur as the disconnecting switch blade 10 isinitially rotated or twisted preparatory to a circuit opening pivotalmovement thereof and to close as the disconnecting switch blade 10approaches or is being twisted into its final closed circuit positionwith respect to the stationary terminal contact 12.

For a description on the operation of the invention, as here disclosed,reference is now made to Sheet-2 of the drawings wherein Figure 3 is aplan view showing the operating parts of the switch with the switchblade 10 in its closed circuit position as shown in Figures 1 and 2 ofthe drawings. Figure 4 shows the relative position of the blade twistingand operating mechanism during the blade twisting period of operationwhich occurs prior to the initial pivotal movement of the switch blade10. Figure 5 shows the position of the parts when the switch bladereaches its full open circuit position. When the switch blade 10 is inits closed circuit position, as shown in Figures 1, 2 and 3 of thedrawings, the shunt forming blade 14 will be in its normal operatingposition with its extending end in engagement with the contact clipcarried by the terminal 13. At

this time as indicated in Figure 3 the shunt circuit forming blade 14will lie closely adjacent to the center line of the circuit breaker.Prior to the initial pivotal circuit opening operation of the switchblade 10, as had been indicated hereinabove, the switch blade 10 will betwisted through a small angle. This will cause the beaver-tail end ofthe switch blade 10 to turn between the opposed contact surfaces of theterminal clip 12 to thus facilitate a separation of the blade 10 and theterminal contact 12. This period of operation is important, particularlywhere switches of this character are exposed to where an accumulation ofice and snow thereupon might seriously interfere with a circuit openingoperation of the switch. Simultaneously, with the twisting of the switchblade 10 in this manner, the shunt circuit forming blade 14 will havemoved out of contact with the terminal clip 15 and into a positionsubstantially corresponding to that shown in Figure 4-. This movementof. the shunt circuit forming blade 14 is explained by the fact that theforked ends of the link which engage with the trunnions 26 upon theblade carrying member 27 tend to adjust themselves with respect to theiruniversal connection with the lever arm 24. This causes the bladecarrying member 27 to turn about the axis of the blade 19. .In otherwords, the free end of the forked link 25 extends downwardly below theaxis of the trunnions 26 and consequently as it is caused to followaround with its universal connection upon the lever on 24 one side ofthe forked link 25 will be put under tension while the other side willbe under compression. This will cause the blade carrying member 27 toturn about its axis and produce the blade twisting operation. Then asthe lever arm 24 continues to move around in its counterclockwisedirection to the position as shown in Figure 5 of the drawings, theforked link 25 will again assume a substantially horizontal position andthe shunt circuit forming blade 14 will have been carried back to aposition closely adjacent to, but still out of contact with the switchclip 15 where it may if desired be protected by a suitable cover againstthe accumulation of ice and snow at this point when the switch is in theopen circuit position. During this movement of the forked link from theposition shown in Figure 4 to the position indicated in Figure 5 theshunt forming blade 14 will gyrate through a small arcuate path in whichat one time it will reach an extreme outer position substantiallycorresponding with that indicated by dot and dash lines in Figure 5 ofthe drawing.

In the above I have described the shunt circuit forming blade 14 asmounted upon a bracket 33 carried by one side of the forked link 25, butit is to be understood that while this arrangement appears to bepreferred, the object of the invention can also be accomplished bymounting the shunt circuit forming blade 14 directly upon the pivotlymounted blade carrying member 34 as shown in Figure 6 of the drawings.In this latter arrangement the pivotly mounted blade carrying member 27is shown as having an integrally cast split clamping socket 35 intowhich the lower end of the shunt circuit forming blade 14 is secured.

While I have, for the sake of clearness and in order to disclose theinvention so that the same can be readily understood, described andillustrated specific devices and arrangements, I desire to have itunderstood that this invention is not limited to the specific meansdisclosed, but may be embodied in other forms and arrangements that willsuggest themselves to persons skilled in the art. It is believed thatthis invention is new and all such changes as come within the scope ofthe appended claims are to be considered as part of this invention.

Having thus described my invention what I claim and desire to secure byLetters Patents is:

1. In a high voltage power line disconnecting device, the combination ofa pivotally mounted air-break disconnecting switch having a blade of thebeaver-tail type, a stationary terminal contact with which thebeaver-tail of said switch blade engages with a twisting motion, meansfor twisting said switch blade as it moves into and out of engagementwith said stationary terminal contact, a high voltage circuit breakerconnected in series circuit with said switch blade having separablecontacts enclosed in an arc confining chamber, an operating mechanismfor moving the separable contacts of said circuit breaker into and outof contact with each other, means forming a shunt circuit around saidcircuit breaker when in its closed circuit position, and meansresponsive to the operation of said blade twisting means for controllingthe operations of said shunt circuit forming means and said circuitbreaker operating mechanism in timed relation with the twistingoperations of said switch blade, whereby said circuit breaker contactswill operate to interrupt the circuit through said disconnecting switchblade during the twisting operation thereof and prior to disengagementof said switch blade with said stationary terminal contact.

2. In a high voltage power line circuit disconnecting device, thecombination of a pivotally mounted air-break disconnecting switch havinga blade of the beaver-tail type, a stationary terminal contact withwhich the beavertail of said switch blade engages with a twistingmotion,

means for operating-and imparting a twisting motion to said switch bladeas it moves into and out of its circuit open and circuit ,closedpositions with respect to said stationary terminal contact, a highvoltage circuit breaker connected in seriescircuit with said switchblade having separable contacts enclosed in an arc extinguishing cham-.her, an operating mechanism for moving the separable contacts of saidcircuit breaker into and .out of contact with each other, meansresponsive to said switch blade twisting means for controlling theoperaton of said operating mechanism in timed relation with theoperations of said switch blade to respectively open and close thecircuit through the separable contacts of said circuit breakeras thebeaver-tail end of said switch blade is twisted into and out of contactwith said stationary contact terminal, and a circuit breaker shortcircuiting blade connected to .and extending from said switch bladeoperating means and movable into shunting relation with the separablecontacts of said circuit breaker as the switch blade is twisted into itscircuit closed position by said operating means and out of saidshuntingrelation with respect to the contacts of said circuit breaker assaid switch blade is twisted preparatory to a circuitdisconnectingoperation.

'3. In anoutdoor power line switching system, the combination of anair-break switchhavingan elongated circuit disconnecting blade mountedfor both a pivotal and a twisting movement as it engages and disengagesa cooperating stationaryterminal contact at the end thereof, a linkagemechanism comprising a vertically extending shaft, a radially extendinglever arm carried by said shaft and a forked-link connected to saidlever arm normally extending over the operating axis of said shaft withits forked end connected to oppositely extending trunnions at the sidesof said switch blade, whereby upon a circuit closing operation of saidlinkage mechanism said switch blade will be caused toIfirst .pivot aboutits pivotal axis from "its open .circuit position and be subsequentlytwisted into contact with .said stationary terminalcontact, an arcconfining circuit breaker connected in series circuit with said switchblade, a line terminal for said circuit breaker having an auxiliaryblade accommodating contact clip, and a'shunt circuit forming bladeconnected to said switch blade adapted and arranged to move intoengagement with said auxiliary blade accommodating contact clip and formashunt circuit in parallel relation with the separable contacts of saidcircuit breaker as said switch blade is twisted into its final circuitclosed position with respect to said stationary terminal contact,whereby said circuit breaker contacts will ,be shunttcircuited by saidauxiliary blade when the disconnecting switch blade is in its ,finalcircuit closed position.

4. In an outdoor powerline switching system, the combination of anair-break disconnected switch having an elongated circuit disconnectingblade mounted for both apivotal and a twisting movement as it engagesand disengages a cooperating stationary terminal contact at the free endthereof, a linkage mechanism comprising an operating, shaft, a radiallyextending lever arm carried by said shaft and 'a 'forked link connectedat one end to said lever 'arm having its forked end connected totrunnions extending'from opposite sides of .said switch blade, wherebyupon a circuit opening operation of said switch blade said linkagemechanism will cause said switch blade to first twist about itslongitudinal axis and then pivot about its pivotal axis into an opencircuit position, a circuit breaker connected'in series circuit withsaid switch blade having separable contacts enclosed in an are confiningstructure, "a lineterminal for said circuit .breaker having'an'auxili'ary blade accommodating contact clip, and an auxiliary shuntforming blade connected to said switch blade movable into shuntcircuitforming engagement with said auxiliary blade accommodatingcontact clip as ,said switch blade is twisted into circuit establishingengagement with said stationary terminal contact, whereby a currentcarrying shunt circuit will 'be estab- Cit switch blade is in itscircuit closed position, said auxili blade being also movable out ofengagement with said auxiliary contact clip by a reverse twisting ofsaid switch blade prior to a pivotal circuit opening movement of saidswitch blade to thus render said circuit breaker operable independentlyof said shunting circuit for an arc free interruption of the power linecurrent and a subsequent air gap isolation by the pivotal movement ofsaid switch blade.

5. in an outdoor power line switching system, the combination of anair-break switch having an elongated circuit disconnecting blade mountedfor both a pivotal circuit closing and a twisting movement forengagement with a cooperating stationary terminal contact at the outerend thereof, a linkage mechanism comprising an operating shaft, aradially extending lever arm upon saidshait and a forked link normallyextending from said lever arm over the axis of said operating shaft andhaving its forked end connected to trunnions extending radially from thelongitudinal axis of said switch blade, whereby upon a circuit openingoperation of said linkage mechanism said switch blade will be firstcaused to twist about its longitudinal axis through a limited angle andthen pivot upon its pivotal support into an open circuit position, avacuum insulated circuit breaker connected in series circuit with saidswitch blade at its pivotally mounted end, a blade accommodating clipconnected to the outer terminal of said circuit breaker disposedsubstantially in the plane of pivotal movement of said switch blade, anda shunt forming blade carried by and extendingfrom said disconnectingswitch blade and engaging said blade accommodating clip, said bladebeing movable out of circuit comple 'ng relation with said bladeaccommodating clip to thus place said circuit breaker in full seriescircuit relation with said disconnecting switch blade without said shuntforming blade when said switch blade is twisted about its axispreparatory to a circuit isolating operation thereof. 7

6. In an outdoor power line switching system, the combination of anairbreak switch having an elongated circuit disconnecting blade mountedfor both a pivotal circuit controlling and a twisting stationaryterminal contact engaging and disengaging movement, an operatingmechanism for imparting said pivotal and twistingmovements to saidswitch blade, whereby upon a circuit opening operation of said operatingmechanism said switch blade will be twisted about its longitudinal axisthrough a limited angle and then pivoted upon its pivotal sup port intoan open circuit position, an arc interrupting circuit breaker connectedin series circuit with said switch blade, a blade accommodating clipconnected to the onter terminal of said circuit breaker, and a shuntforming blade connected to and mounted upon the pivotal end of saiddisconnecting switch blade engaging said blade accommodating clip andmovable in a plane at a right angle to the plane in which saiddisconnecting switch blade operates and out of circuit completingrelation with said blade accommodating clip to thus open the circuitformed by said shunt forming blade as said switch blade is twisted aboutits axis preparatory to a circuit isolating operation thereof.

7. In an outdoor power line switching system, the combination of anair-break switchghaving an elongated circuit disconnecting blade mountedfor both a pivotal circuit controlling and'a twisting stationaryterminal contact engaging movement, an operatingmechanism for impartingthe pivotal and twisting movements to said switch blade, whereby upon acircuit closing operation of said' operating mechanism said switch bladewill be caused to twist about its longitudinal axis through a limitedangle and then move upon its pivotal support from its open circuitposition and finally twisted into engagement with said stationaryterminal contact, an

are interrupting circuit breaker connected in series circuit with saidswitch blade, an auxiliary blade accommodating clip connected to theouter terminal of said circuit breaker disposed substantially in theplane of pivotal movement of said switch blade, and a shunt formingblade connected to said disconnecting switch blade and engaging saidblade accommodating clip, said shunt forming blade being movable intocircuit completing relation with said blade accommodating clip as thedisconnecting switch blade is twisted about its axis during the finalcircuit closing operation thereof to thus connect said shunt formingblade in parallel line current carrying relation with said circuitbreaker.

8. In a high voltage circuit interrupting switch, the combination of apivotally mounted disconnecting switch blade having a flattenedbeaver-tail end, a stationary terminal contact having opposed contactsurfaces engageable by the beaver-tail end of said switch blade whentwisted into right angled relation therebetween, means for operatingsaid switch blade and imparting a twisting motion thereto as thebeaver-tail end of said switch blade is pivotally moved into and out ofengaging relation with said stationary terminal contact, a high voltagecircuit breaker connected in series circuit with said switch bladehaving separable contacts operating in an arc suppressing medium, meansfor moving the separable contacts of said circuit breaker into and outof circuit establishing contact with each other, and a shunt circuitforming conductor carried by said switch blade movable in response to anoperation of said means for imparting the pivotal and twisting motion tosaid switch blade, the operation of said shunt forming conductor beingtimed to provide a shunt circuit around the contacts of said circuitbreaker assaid switch blade is twisted into its final circuit closedposition with respect to said stationary contact andto ,becomeinoperative as a shunt around the contacts of, said circuit breakerduring the initial twisting and circuit opening operation of saiddisconnecting switch blade.

9. In a power line load current disconnecting switch, the combination ofan air-break circuit isolating switch having a pivotally mounted circuitdisconnecting blade with a beaver-tail end that engages a stationaryterminal contact with a twisting motion, a trip free arc extinguishingcircuit breaker mounted adjacent the pivotal end of said switch bladeand connected in series circuit between said switch blade and a lineterminal, a switch blade operating mechanism for imparting a combinedpivotal and twisting movement to said switch blade, a bladelikeconductor connected to an extending at substantially a right angle tothe longitudinal axis of said switch blade adapted :and arranged toengage said contact clip and form a current shunting circuit around saidcircuit breaker when said switch blade is in its circuit closed positionand to be moved out of circuit completing relation with said contactclip by a twisting operation of said switch blade prior to a pivotalpower line circuit opening operation of said switch blade, and a circuitbreaker tripping mechanism also controlled by said switch bladeoperating mechanism timed to trip said circuit breaker and open thecircuit through said switch blade upon a twisting thereof and prior inpoint of time to an effective circuit interrupting pivotal movement ofsaid switch blade.

10. In a power line load current disconnecting switch, the combinationof an air-break circuit isolating switch having a pivotally mounteddisconnecting switch blade with a beaver-tail end that engages astationary contact terminal with a twisting motion, an arc extinguishingcircuit breaker connected in series with said circuit switch blade and aline terminal, a contact clip carried by the line terminal of saidcircuit breaker, a switch blade operating mechanism for imparting acombined twisting and pivotal movement to said switch blade, ablade-like conductor connected to and extending at substantially a rightangle to the longitudinal axis of said switch blade adapted and arrangedto engage said contact clip and from a cur- 1 rent shunting cricuitaround said circuit breaker when said switch blade is in its circuitclosed position and to be moved out of engagement with said contact clipduring the initial twisting of said switch blade during a circuitopening operation thereof, whereby said shunt circuit will be opened andsaid circuit breaker contacts will be connected. independently of saidshunt circuit in series circuit when said switch blade is initiallytwisted for a circuit isolating operation, and a circuit breakeroperating mechanism responsive to a blade twisting operation of saidswitch blade operating mechanism for effecting a power line circuitinterrupting operation of said circuit breaker as the switch blade istwisted and prior in point of time to an etfective circuit isolatingpivotal movement of said switch blade.

11. In an outdoor power line switching system, the combination of anair-break switch having an elongated circuit isolating blade mounted forboth a pivotal circuit opening and a twisting movement as it engages anddisengages a cooperating stationary terminal contact at the outer endthereof, a linkage mechanism comprising an operating shaft, a radiallyextending lever arm upon said shaftand a forked-link extending from saidlever arm with its forked end connected to trunnions extending radiallyfrom the twisting axis of said switch blade, whereby upon a circuitopening operation of said linkage mechanism said switch blade will becaused to first twist about its longitudinal axis through a limitedangle and then pivot upon its pivotal support into an open circuitposition, a vacuum insulated circuit breaker connected in series circuitwith said switch blade, a blade accommodating clip connected with a lineterminal of said circuit breaker disposed substantially in the plane ofpivotal movement of said switch blade, and a shunt forming bladeextending from said disconnecting switch blade normally engaging saidblade accommodating clip, said shunt forming blade being movable in aplane at substantially a right angle to the plane in which saiddisconnecting switch blade operates and out of circuit establishingrelation with said blade accommodating clip during the twistingoperation of said switch blade, whereby said circuit breaker will beconnected in series circuit with the disconnecting switch blade withoutthe shunt circuit formed by said shunt circuit forming blade when saidswitch blade is operated to open the circuit.

12. In a high voltage circuit interrupting switch, the combination of apivotally mounted disconnecting switch blade having a flattenedbeaver-tail end, a stationary terminal contact having opposed contactsurfaces engageable by the beaver-tail end of said switch blade whentwisted into right angled relation therebetween, means for operatingsaid switch blade and imparting a twisting motion thereto as thebeaver-tail end of said switch blade is pivotally moved into and out ofengaging relation with said stationary terminal contact, a high voltagecircuit breaker connected in series circuit with said switch bladehaving a power line terminal and separable contacts operating in an arcsuppressing medium, spring means for moving the separable contacts ofsaid circuit breaker into and out of circuit establishing contact witheach other, and a shunt circuit forming conductor carried by said switchblade and movable into and out of contact with said circuit breaker lineterminal and in response to the blade twisting-operations of said meansfor imparting the pivotal and twisting motions to said switch blade, theoperation of said shunt forming conductor being timed to form a shuntcircuit around said circuit breaker as said switch blade is twisted intoits final circuit closed position and to become inoperative as a shuntas the switch blade is twisted prior to the pivotal circuit openingoperation of said switch blade.

13. In a high voltage arc free circuit interrupting and isolatingswitching means, the combination of a pivotally mounted circuitdisconnecting: switch" blade; a stationary breaker line.terminalcontact, and meansforicontrolling" theposition'of said shunt.forming conductor with respect to said circuit breaker line terminalcontact in timed relation with the circuit opening and closing movementsof said switch bladewith respect to said stationaryterminal contact,wherebysaidshunt circuitfforming conductor will be'moved'into engagementwithsaid circuit'breaker lineterminal contact as said switchbladem'ovesin'its final closed circuit position and-moved'outof'engagement'with' said circuit breaker line terminal contactupon aninitial circuit openingoperation of'said switch blade;

14% In an outdoor power line switching system, the combination of anair-break switch? having an elongated circuit isolating blade mountedfor pivotal circuit opening and closing movements with respect to. astationary terminalcontact at the outer end thereof; alva'cuum insulatedcircuit breaker connected in' series circuit with said switch blade, aline terminal'for said circuit breaker having a blade accommodatingclip'disp'osed substantiallyin the plane of pivotal movement ofsaidswitch' blade, and a shunt circuit forming'blade extendingfrom thepivotal end of said disconnecting switch blade normally engaging saidblade accommodating. clip,- said shunt circuit forming blade being.movable in'a plane at substantially a right opening operation" of saidSwitchblade, whereby said ci-rcn'itbreakerwill operate infull' seriescircuit with said v 12 angle to the"plane? in which said" disconnectingswitch bladeoperatesandoutof circuit establishing relation with saidblade accommodating clip during the initial circuit disconnecting"switch blade when said switch blade is operated to open the circuitthercthrough.

'15. Ina-highvoltage circuit interrupting switch, the combination of apivotall'y'mounted' disconnecting switch blade; a stationary terminalcontact'having opposed contactsurfaces engageable by the free end ofsaid switch blade; means for operating said switch blade and imparting,a pivotal movement into and out'of engaging relation with saidstationary terminal contact, a high'voltage circuit breaker connected inseries circuit with said switch blade having a power line terminalandseparablecontacts. operating in an arc suppressing medium, means formoving theseparablecontacts of said circuit breaker into and out ofcircuit establishing contact'with each other, andfaj shunt circuitforming conductor carried by said switch blade and movable into and outof contact with said'circuit breaker line terminal, and means responsiveto the means for imparting pivotal movement to said switchblade formoving said shunt circuit forming conductor in timed relation therewithto form av shunt circuit" around said circuit breaker as said'switchblade is moved intoits" final" circuit closed position and to become.inoperative asa shunt upon'an initial circuit opening movement ofsaid'switch blade.

References Cited in'the file of this patent UNITED STATES PATENTS2,480,622 Warnock Aug. 30, 1949 2,601,138 Hart .Iune'17, 1952'-2,697,l53 Owenset al. Dec. 14, 1954' 2,769,063 Lingal Oct. 30, 1956'

